In this Sunday, Jan. 25, 2015, photo, a police officer stands in front of a home in Eagan, Minn. A 15-year-old boy unintentionally fatally shot his 13-year-old brother while playing "cops and robbers" after the boys discovered their father's hidden gun. (AP Photo/Star Tribune, Carlos Gonzalez) MANDATORY CREDIT
(The Associated Press)

In this Sunday, Jan. 25, 2015, photo, a police officer stands in front of a home in Eagan, Minn. A 15-year-old boy unintentionally fatally shot his 13-year-old brother while playing "cops and robbers" after the boys discovered their father's hidden gun. (AP Photo/Star Tribune, Carlos Gonzalez) MANDATORY CREDIT
(The Associated Press)

EAGAN, Minn. – Police in Minnesota say a 15-year-old boy unintentionally fatally shot by his 13-year-old brother while playing "cops and robbers."

Police and paramedics responded to an Eagan home Sunday morning after the 15-year-old reported his brother was unresponsive and bleeding.

The 15-year-old told dispatchers his brother had fallen and stabbed himself while running with a knife. But when police arrived, the older boy told officers he had accidentally shot his brother.

The boys were home alone with their 11-year-old sister when they found an unloaded 9 mm pistol belonging to their father. Investigators say at some point, the firearm was loaded, then thought to be unloaded while the boys chased each other.

Police say the 15-year-old fired one round that struck his brother in the chest.